looks to me like once you've got the ball to the top of the wall you somehow have to get the ball and the big cog it's attached to to swap places. But just how to do that last part I'm not sure yet.

Hint (okay, maybe it's more than just a hint): Drop a BIG C in the middle of the two gears. The C will ride up and fall back down when the gears reach the top. At the top of the two tracks, you see notches. If you draw a horizontal line across the gap that completely fills those notches (with no space on either side), the gear with the ball will slide to the left. If you do that perfectly, you'll be able to just delete the C you drew earlier and then delete the line when the ball is over the orbs. [If getting the line perfectly in the notches poses a problem, you can draw a line that goes from the 1st notch below the top over to the same notch on the left.] If the line isn't perfect, you can give the ball a push by dropping a wedge above it, or with a curved line to the right of it.